A recent visit on LinkedIn allowed me to see the new Q&A function that captured my attention. The workflow is smooth and this is the best way to connect your network for an information request I have seen so far. On his ConversationBlog I recomend, Philippe Borremans took the time to describe the functionalities in the article LinkedIn starts business related Q&A service. Have a look.
Also, if you are not LinkedIn savvy or if you would like to deepen your understanding and use of it, Guy Kawasaki published a clear and crisp “manual” that you can check here: Ten Ways to Use LinkedIn